1. Technical Field
The present invention relates to a cooling device and a projector.
2. Related Art
There has been known a projector that includes a light source device, an optical modulator that modulates a light beam irradiated from the light source device in accordance with image information to form an optical image; and a projection optical device that projects the optical image in an enlarged manner.
In the projector, when dust, lamp black or the like is attached on a surface of the optical modulator, image quality of a projected image is deteriorated. In addition, since the optical modulator such as a liquid crystal panel is generally heat-sensitive, the optical modulator may be deteriorated due to heat caused by irradiation of a light beam from the light source device.
Accordingly, to ensure stable image quality of the projected image and to efficiently cool the optical modulator, an arrangement has been suggested in which the optical modulator is disposed in a sealed structure, air in the sealed structure is circulated by a circulation fan, and heat in the air in the sealed structure is released to the outside of the sealed structure by a cooling device that uses a thermoelectric conversion element such as a peltiert element (see, for example, Document: JP-A-2000-298311).
The cooling device described in the document includes: a thermoelectric conversion element; two heat transfer members sandwiching and holding the thermoelectric conversion element; and a cooling fan for cooling a heat transfer member disposed on a heat releasing side. The heat transfer member disposed in the sealed structure out of the two transfer members is formed with a plate member made from aluminum having heat transfer property. The heat transfer member disposed outside the sealed structure is formed with a heat releasing fin made from aluminum having heat transfer property.
In the arrangement, since a surface area of the heat transfer member disposed in the sealed structure is comparatively small, it is difficult that the heat in the air in the sealed structure is appropriately absorbed by the heat transfer member. In other words, a heat absorption amount transferred to a heat absorbing surface of the thermoelectric conversion element via the heat transfer member is comparatively small, so that it is difficult to enhance a ratio of a heat absorption amount of heat absorbed from a to-be-cooled object (the air in the sealed structure) to an electric power consumption of the cooling device (the heat absorption efficiency).